Pretreated epoxidation catalyst and a process for producing an olefin therewith

ABSTRACT

A pretreated titanium silicalite with MFI structure (TS-1) catalyst which has been pretreated with methanol, and then optionally filtered and optionally air-dried to form a pretreated activated TS-1 catalyst. The activated TS-1 may be used in an epoxidation reaction with no additional methanol added and has equivalent activity to TS-1 used with large excesses of methanol. By removing the need for additional methanol during the reaction, the losses of epichlorohydrin from solvolysis are minimized significantly.

CLAIM OF PRIORITY

This Application is a Divisional Application of U.S. National Stageapplication Ser. No. 13/636,706, filed Sep. 24, 2012 and published asU.S. Publication No. 2013/0012731 on Jan. 10, 2013, which claims thebenefit to International Application Number PCT/US2011/000521, filedMar. 22, 2011 and published as WO 2011/119215 on Sep. 29, 2011, whichclaims the benefit to U.S. Provisional Application 61/317,383, filedMar. 25, 2010, the entire contents of which are incorporated herein byreference in its entirety.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to catalysts for use in chemicalreactions. More specifically, the present invention relates to apretreated catalyst for use in reactions such as a process for producingan oxirane by reacting an olefin and a peroxide compound in the presenceof the pretreated catalyst. Even more specifically, the presentinvention relates to, for example, a process for epoxidizing allylchloride to epichlorohydrin using the pretreated catalyst such as apretreated titanium silicalite catalyst.

2. Description of Background and Related Art

The reaction of epoxidizing allyl chloride to epichlorohydrin using atitanium silicalite catalyst and hydrogen peroxide (H₂O₂) is a wellknown process such as disclosed in, for example, U.S. Pat. No.7,323,578. To date, the known processes for epoxidizing allyl chlorideto epichlorohydrin have not been commercialized.

It is also well known that methanol is a necessary reaction component ofthe process of epoxidizing allyl chloride to epichlorohydrin to obtainhigh activity with a titanium silicalite catalyst; and typically, insuch known processes methanol is used in large excesses (50-90 weightpercent) to ensure that the reaction mixture remains as one liquidphase. However, the use of a large excess of methanol results in theformation of byproducts from the reactions of methanol and water, whichare solubilized in the organic phase by methanol, with epichlorohydrin.These large quantities of methanol also result in estimations of largetowers and high energy consumption for predicted purification on acommercial scale.

In addition, problems of low olefin selectivity and of difficultseparations exist in the known processes; however, such problems can besolved by reducing the methanol concentration or removing methanolentirely from the processes. Still, in the epoxidation of many olefins,reducing or eliminating methanol concentration in the known processescreates a reaction system with two liquid phases, which results in lowerepoxide yield, lower H₂O₂ selectivity to epichlorohydrin, and/or longerreaction times.

Chinese Patent Application No. CN 200710039080.1 describes reactionconditions for epoxidizing allyl chloride to epichlorohydrin withtitanium silicalite and H₂O₂ without the presence of any solvent,including methanol. The teachings of CN 200710039080.1 include a molarratio of allyl chloride to H₂O₂ from 1-100:1, a weight ratio of H₂O₂ tocatalyst from 0.2-200, reaction temperatures from 25-100° C., pressuresfrom 0.1-0.2 MPa, and reaction times from 0.1-48 hours. The catalystused is titanium silicalite and the ratio of SiO₂/TiO₂ is 10-200. Theexamples described in CN 200710039080.1 have H₂O₂ conversions greaterthan 95 percent (%) and H₂O₂ to epichlorohydrin selectivities greaterthan 92%. However, using commercially available titanium silicalitecatalyst under the conditions given in CN 200710039080.1 results in aH₂O₂ to epichlorohydrin selectivity as low as 81%. CN 200710039080.1mentions that its “solvent-less system” simplifies and reduces energyconsumption in the separation and purification of the products, but CN200710039080.1 does not provide any examples or evidence of energyreduction using its process.

SUMMARY OF THE INVENTION

The present invention is directed to a modified titanium silicalite-1with MFI structure (TS-1) catalyst and to a process for making suchmodified catalyst.

In one embodiment, the present invention includes a modified TS-1catalyst comprising a TS-1 catalyst which has been treated with methanolprior to the use of the catalyst. Optionally, the catalyst can furtherbe filtered and/or air dried prior to the use of such modified catalyst.The TS-1 catalyst of the present invention is modified before thecatalyst is used in a chemical reaction, resulting in activation of theTS-1 by the pretreatment with methanol. No additional solvent isnecessary in the reaction composition, which promotes the formation oftwo liquid phases.

By pre-treating a TS-1 catalyst with methanol, then optionally,filtering the catalyst, and then optionally, air-drying the catalyst, aresulting pretreated activated catalyst can be obtained. This activatedTS-1 may be used in an epoxidation reaction without adding methanol tothe reaction mixture. The activated TS-1 catalyst of the presentinvention has a catalytic activity equivalent to known TS-1 catalyststhat use large excesses of methanol during a reaction using theun-modified catalyst. By eliminating the need for additional methanolduring the reaction, the losses of epichlorohydrin from solvolysis areminimized significantly by utilizing the pre-treated catalyst of thepresent invention. The present invention also solves the problem ofcostly separation units required to isolate epoxides from reactionscarried out in the presence of 50 wt % or more of methanol.

In other embodiments, the pretreated catalyst of the present inventioncan also be used to epoxidize other olefins; or to oxidize aliphatic oraromatic hydrocarbons.

Another embodiment of the present invention is directed to a process forusing the above catalyst in a chemical reaction process. For example, ina preferred embodiment, the catalyst of the present invention may beused in the epoxidation of allyl chloride to epichlorohydrin by hydrogenperoxide wherein the epoxidation is catalyzed by the TS-1 catalyst whichhas been activated by pretreatment with methanol in accordance with thepresent invention. The reaction is carried out in two liquid phases withno additional methanol added. The advantages that the system of thepresent invention offers are decreased losses of epichlorohydrin bysolvolysis and decreased energy costs for separation, while maintainingfast reaction times.

The present invention is advantaged compared to those of the prior artwhich use 50 wt % or more methanol because the separation and isolationof the epoxide from the reaction mixture is facilitated. The removal ofmethanol as a solvent results in the formation of two liquid phases,which can be decanted after the reaction to obtain an epoxide-richorganic phase. The present invention process is advantaged compared tothe prior art processes, for example as disclosed in CN 200710039080.1,because by pre-treating the catalyst with methanol and then using themodified catalyst of the present invention in a process, a higherselectivity of H₂O₂ to olefin, a higher olefin yield, and a higherselectivity of olefin versus byproducts can be achieved.

The present invention creates an advantage over conditions used in, forexample, CN 200710039080.1, where no methanol is used, by increasing theyield for example by 10% or more, while decreasing the byproducts forexample by over 50%. The present invention also presents an advantageover reactor compositions which use amounts of methanol of 50 wt % orhigher as a solvent by decreasing by at least 80% the formation ofchloromethoxypropanol, the main byproduct in these types of reactions.

Another advantage of the present invention is lower equipment cost andlower energy usage due to not having to separate out, recover and/orrecycle methanol when used as a solvent in a reaction mixture.

BRIEF DESCRIPTION OF THE DRAWINGS

For the purpose of illustrating the present invention, the drawing showsa form of the present invention which is presently preferred. However,it should be understood that the present invention is not limited to theembodiments shown in the drawing.

FIG. 1 shows the derivative weight loss by thermogravimetric analysis(TGA) of a sample of activated TS-1 catalyst which has been pretreatedwith methanol in accordance with the present invention. FIG. 1 shows afirst peak for the evolution of non-bound methanol present in the poresof the catalyst at approximately 60° C., and a second peak for theevolution of Ti-bound methanol at approximately 300-400° C.

DETAILED DESCRIPTION OF THE INVENTION

One broad embodiment of the present invention comprises an activatedcatalyst for use in chemical reactions, wherein the catalyst comprises apre-treated catalyst which has been pretreated with methanolsufficiently to activate the catalyst. The pretreated catalyst may befiltered and air-dried resulting in a pretreated activated catalystuseful for various oxidation processes.

Another broad embodiment of the present invention includes a process foroxidizing olefins using the pretreated catalyst such as for example inthe epoxidation of olefins to oxides.

The process for preparing an activated catalyst of the present inventioncomprises a pretreating titanium silicalite catalyst with MFI structure(TS-1 catalyst) with methanol. The pretreating step includes forexample, the step of contacting TS-1 catalyst with methanol underconditions to have the methanol bond to the TS-1 catalyst prior to useof the catalyst.

The catalyst useful in the present invention includes known titaniumsilicalite catalyst structures. The TS-1 catalyst used in the presentinvention may be selected from commercially available catalysts such asTS-1 from SW Chemie, Polimeri Europa, or Clean Science, for example.Alternatively, the TS-1 catalyst can be manufactured by any of the knownprocesses in the art such as those described in U.S. Pat. No. 4,410,501,for example.

In other embodiments of the present invention, other titanium silicatesmay be used such as titanium-silicalites with a MEL or intermediateMFI/MEL structure and titanium-silicalites from beta zeolites containingtitanium and having a BEA structure. Other titanium containing zeolitecatalysts generally known as TS-2, TS-3, Ti-MCM-22, Ti-MWW, ZSM-48 andZMS-12 can also be used for preparing the catalyst of the presentinvention.

The concentration of the TS-1 catalyst used in the present invention isgenerally from about 0.1 weight percent (wt %) to about 50 wt %;preferably from about 0.1 wt % to about 25 wt %; and more preferablyfrom about 1 wt % to about 10 wt %.

The methanol useful in the present invention includes known methanolcompounds commercially available such as methanol from FisherScientific.

The amount of methanol (MeOH) used to pretreat the TS-1 catalyst isgenerally at a mole ratio of MeOH to TS-1 catalyst of from about 0.1:1MeOH:TS-1 to about 100:1 MeOH:TS-1; preferably, from about 1:1 MeOH:TS-1to about 100:1 MeOH:TS-1; more preferably, from about 1:1 MeOH:TS-1 toabout 50:1 MeOH:TS-1; and most preferably, from about 5:1 MeOH:TS-1 toabout 10:1 MeOH:TS-1.

The fraction (the at least a portion) of titanium that is chemicallybonded with methanol in TS-1 catalyst generally is from about 50% toabout 200%, preferably from about 100% to about 200%, and morepreferably from about 150% to about 200%; as determined by infrared (IR)spectroscopy and TGA; and based on the theory that each Ti molecule canbind two MeOH molecules.

Generally, the process of pretreating the catalyst includes for examplecontacting a TS-1 catalyst with the methanol at a temperature of fromabout −20° C. to about 60° C., preferably from about 0° C. to about 60°C., and more preferably from about 25° C. to about 60° C. The contactingstep may be carried out by known methods and equipment such asmechanical stirring, flowing through a packed catalyst bed, or soakingin a container; and the like.

The contacting step can be carried out for a pre-determined period oftime sufficient to bond the methanol to the TS-1 catalyst, such as forexample, generally for about 1 minute to about 24 hours, preferably fromabout 5 minutes to about 1 hour, and more preferably from about 30minutes to about 1 hour.

After the contacting step, the pretreated catalyst may be separated fromthe excess methanol from the catalyst. Any separation method known inthe art may be used such as filtering, centrifuging, evaporating,decantation, and the like.

Optionally, the isolated pretreated catalyst may be dried before orafter filtering the catalyst. Any drying method known in the art may beused to dry the catalyst such as by flowing air, placement in adessicator, or placement in an oven at temperatures below about 65° C.with or without the presence of air.

After isolating the pretreated catalyst, the pretreated catalyst may beused in various chemical reaction processes such as epoxidations,hydroxylations, or other oxidation reactions.

As aforementioned, the pretreated catalyst product of the presentinvention preferably contains at least a portion of methanol chemicallybonded to titanium atoms of the catalyst. The fraction of titanium thatis chemically bonded with methanol in TS-1 catalyst generally is fromabout 50% to about 200%, preferably from about 100% to about 200% andmore preferably from about 150% to about 200%; as determined by IRspectroscopy at a frequency of 950-970 cm⁻¹, depending on the TS-1catalyst crystal size; and based on the theory that each Ti molecule canbind two methanol molecules.

The chemisorption of MeOH onto Ti causes a shift in the frequency of theTi—O stretch to higher wavenumbers. The chemisorption is also evidencedby evolution of material in a TGA at approximately 400° C. Optionally,there may be methanol that is not chemically bonded but may be retainedand present in the pores of the catalyst as well. This is not seen inthe IR spectrum at the indicated range, and evolves at approximately 65°C. in the TGA.

For example, a sample of TS-1 catalyst with a crystal size ofapproximately 0.1-0.3 μm was pretreated with methanol at roomtemperature for 1 hour, and then filtered and air-dried. Thenon-activated catalyst had a peak at 963.6 cm⁻¹, which shifted to 968.0cm⁻¹ upon chemisorption of methanol. As shown in FIG. 1, TGA of anactivated methanol-pretreated catalyst shows the evolution of non-boundmethanol in the pores of the catalyst at approximately 60° C., and theevolution of Ti-bound methanol at approximately 300-400° C.

The pretreated catalyst of the present invention may be used in aprocess for oxidizing an olefin including reacting an olefin with anoxidant in the presence of the pretreated catalyst and under reactionconditions to prepare an epoxide; wherein the oxidizing reaction (alsoreferred to herein as an epoxidation reaction) is catalyzed by themethanol pretreated TS-1 catalyst of the present invention which hasbeen activated by pretreatment with methanol as described above.

As an illustration of one embodiment of the use of the pretreatedcatalyst of the present invention, the pretreated catalyst may be usedin a process for preparing epichlorohydrin by epoxidizing allyl chloridewith hydrogen peroxide in the presence of the activated methanolpretreated TS-1 catalyst of the present invention.

The reaction mixture including an olefin comprises a multiple liquidphase composition useful for preparing an oxirane product. The olefinused in the reaction mixture includes, for example: (a) at least oneolefin; wherein the olefin is selected from one of (i) an aliphaticolefin or substituted aliphatic olefin, with the proviso that thealiphatic olefin is not propylene, (ii) a cycloaliphatic olefin, (iii)an aromatic olefin, (iv) a cycloaromatic olefin, and (v) mixturesthereof.

Embodiments of the olefin used in the epoxidation reaction of thepresent invention may include for example chloride-butadiene and otherlinear dialkenes; cyclohexene and other cyclic alkenes and dialkenes;substituted alkenes, such as halogenated alkenes, styrene,divinylbenzene, dicyclopentadiene; other aromatic alkenes; and mixturesthereof. Moreover, butenes, pentenes, hexenes, octeneheptenes-1,1-tridecene, mesityl oxide, isoprene, cyclo-octane, cyclohexene orbicyclic compounds such as norbornenes or pinenes may also be used inthe process. In a preferred embodiment, the olefin used in the presentinvention is ally chloride.

The allyl chloride useful in the epoxidation process of the presentinvention includes known allyl chloride compounds. Alternatively, theallyl chloride can be manufactured by known processes such asthermochlorination.

The concentration of the allyl chloride used in the epoxidation processis generally from about 10 wt % to about 90 wt %, preferably from about20 wt % to about 80 wt %, and more preferably from about 30 wt % toabout 70 wt %.

The oxidant useful in the epoxidation process of the present inventionincludes known oxidant compounds such as peroxocompounds such as ahydroperoxide including for example hydrogen peroxide, commerciallyavailable from Fisher Scientific. Examples of other hydroperoxides thatmay be used include, but are not limited to, tert-butyl hydroperoxide,ethylbenzene hydroperoxide, acetyl peroxide, benzoyl peroxide, methylethyl ketone peroxide, cumene peroxide, and combinations thereof.

In one embodiment of the present invention, the epoxidation of allylchloride may be carried out preferably using hydrogen peroxide. Anadvantage of this process is the avoidance of forming by-products and/orco-products.

The concentration of the oxidant used in the epoxidation process isgenerally from about 1 wt % to about 30 wt %, preferably from about 1 wt% to about 15 wt %, and more preferably from about 1 wt % to about 7 wt%.

Generally, the epoxidation process of the olefin includes for examplemixing the olefin with an oxidant at a temperature of from about 0° C.to about 60° C., preferably from about 10° C. to about 50° C., and morepreferably from about 25° C. to about 45° C. The mixing step may becarried out by known methods and equipment such as a stirred batchreactor, a plug flow reactor, a continuously stirred tank reactor, afluidized bed reactor, a loop reactor, or a tubular reactor, and thelike.

After the above mixing step, the resultant epoxy may be recovered fromthe reaction mixture. Any recovery method known in the art may be usedsuch as decantation, extraction, evaporation, or distillation, and thelike.

After isolating the epoxide, the epoxide may be further used as anintermediate product in various processes such as for making coatingsand composites.

In the process of producing an epichlorohydrin from allyl chloride, theprocess steps may include the following steps: addition of reactants,mixing the reactants in the presence of a catalyst, separation of thereactants from the catalyst, separation of epichlorohydrin from thereaction mixture, and optionally recycle of unreacted allyl chlorideand/or solvents.

Some of the advantages of the process of the present invention includefor example, (1) no methanol is needed or used to prepare an epoxideproduct, for example in the process of producing epi, the use of nomethanol facilitates separation and isolation of the desiredepichlorohydrin product; (2) an increase in yield of epoxide product,for example in the process of producing epichlorohydrin, the epi yieldis preserved, while the losses of epichlorohydrin to byproducts isreduced; (3) a decrease in methanol byproducts production, thusproviding a purer epoxide product; and (4) lower equipment cost andlower energy usage due to not having to separate out, recover and/orrecycle methanol when used as a solvent in a reaction mixture.

EXAMPLES

The following examples and comparative examples further illustrate thepresent invention in detail but are not to be construed to limit thescope thereof. Unless otherwise indicated, all parts and percentages areby weight. Unless otherwise specified, all instruments and chemicalsused are commercially available.

In the following Examples, various terms and designations are used suchas for example, “GC” stands for gas chromatography; “epi” stands forepichlorohydrin; “biphasic” means two liquid phases which are present inaddition to any solid or gas phases which may be present in a reactionmixture.

In the following Examples, standard analytical equipment and methods areused including the following:

Gas chromatography (GC) was performed on an HP 6890 series G1530A GCwith a JP 7682 series injector and flame ionization detector.

The amount of hydrogen peroxide was analyzed by iodometric titrationusing 0.01 normality (N) sodium thiosulfate. The hydrogen peroxideconcentration was calculated as follows: parts per million (ppm)hydrogen peroxide=(milliliter (ml) titrant used) (0.01N) (17000)/gsample. Titrations were performed using a Mettler Toledo DLSx V2.3titrator with a DM140 sensor.

Example 1 Part A.—Pretreatment of the TS-1 Catalyst

TS-1 catalyst (6.90 g) was stirred with MeOH (50 mL) at 25° C. for 1hour. The catalyst was vacuum filtered through a 0.45 μm filter paperand air-dried in a desicator. The resulting TS-1 catalyst prepared thisway will hereafter be referred to as the “pretreated TS-1 catalyst.”

Part B.—Epoxidation Process using the Pretreated TS-1 Catalyst

Allyl chloride (363.10 g, high purity, 99.6%, obtained from The DowChemical Company and pretreated TS-1 catalyst (7.173 g, Si/Ti˜30)prepared in Part A. above were added to a 750-mL jacketed glass reactorwith a stainless steel cooling coil, thermocouple, mechanical stirrer,addition funnel, N₂ purge with gas scrubber, and reflux condenser/coldfinger combination. 32 wt %/aqueous (aq.) hydrogen peroxide (80.02 g)was charged to the addition funnel, and then added to the reactor slowlyafter the allyl chloride/catalyst mixture was brought to 25.5° C. Themixture was stirred at 600 rpm, and the reaction was maintained atapproximately 25° C. using the cooling coil.

After 300 minutes, the reactor contents of the reactor were drainedequally into two 250 mL centrifuge tubes, and then centrifuged at 3000rpm and 0° C. for 30 minutes. The liquid was decanted from the catalystinto a separatory funnel, where resultant organic and aqueous phaseswere collected separately.

Both the organic and aqueous phases were analyzed by GC; and the amountof peroxide remaining was determined by titration with sodiumthiosulfate. The results of this Example 1 are reported in Table I.

Comparative Example A Methanol Solvent/Single Phase Reaction Conditions

Allyl chloride (115.30 g, high purity, 99.6%, obtained from The DowChemical Company, TS-1 catalyst (6.900 g, Si/Ti˜30), and methanol(201.25 g), were added to a 750-mL jacketed glass reactor with astainless steel cooling coil, thermocouple, mechanical stirrer, additionfunnel, N₂ purge with gas scrubber, and reflux condenser/cold fingercombination. 32 wt %/aq. hydrogen peroxide (80.01 g) was charged to theaddition funnel, and then added to the reactor slowly after the allylchloride/catalyst/methanol mixture was brought to approximately 25° C.The mixture was stirred at 600 rpm, and the reaction was brought up to40° C. by the reaction exotherm and maintained at approximately 40° C.using the cooling coil.

Samples of the reaction mixture were filtered using a 0.45 μm syringefilter to remove any catalyst particles, and then analyzed by GC.

When the reaction was deemed complete by epi analysis via GC (after 75minutes), the reactor contents were drained equally into two 250 mLcentrifuge tubes, and then centrifuged at 3000 rpm and 0° C. for 30minutes. The liquid was decanted from the catalyst and analyzed by GCand the amount of peroxide remaining was determined by titration withsodium thiosulfate. The results of this Comparative Example A arereported in Table I.

Example 2 Part A.—Pretreatment of the TS-1 Catalyst

TS-1 catalyst (6.6469 g, Si/Ti=˜30) was stirred with MeOH (50 mL) at 25°C. for 1 hour. The catalyst was vacuum filtered through a 0.45 μm filterpaper and air-dried in a dessicator resulting in a modified catalyst(hereafter “pretreated TS-1 catalyst”).

Part B.—Epoxidation Process using the Pretreated TS-1 Catalyst Allylchloride (268.9 g, high purity, 99.6%, obtained from The Dow

Chemical Company and all of the pretreated TS-1 catalyst prepared inPart A. above were added to a 750-mL jacketed glass reactor with astainless steel cooling coil, thermocouple, mechanical stirrer, additionfunnel, N₂ purge with gas scrubber, and reflux condenser/cold fingercombination. 30 wt %/aq. hydrogen peroxide (39.88 g) was charged to theaddition funnel, and then added to the reactor slowly after the allylchloride/catalyst mixture was brought to about 25° C. The mixture wasstirred at 600 rpm, and the reaction was brought up to 40° C. by thereaction exotherm and maintained at about 40° C. using the cooling coil.

After 60 minutes, the reactor contents were drained equally into two 250mL centrifuge tubes, and then centrifuged at 3000 rpm and 0° C. for 30minutes. The liquid was decanted from the catalyst into a separatoryfunnel, where resultant organic and aqueous phases were collectedseparately.

Both the organic and aqueous phases were analyzed by GC; and the amountof peroxide remaining was determined by titration with sodiumthiosulfate. The results of this Example 2 are reported in Table I.

Comparative Example B Biphasic Reaction Conditions

In this Comparative Example B, a biphasic reaction was carried out whereno MeOH is added as a solvent, and the catalyst was not pretreated. Theconditions in this Comparative Example B are similar to the conditionsreported in Chinese Patent Application No. CN 200710039080.1, exceptthat the TS-1 catalyst used in this Comparative Example B was purchasedfrom Süd Chemie.

In carrying out this Comparative Example B, allyl chloride (400.62 g,epi grade, 99.4%, obtained from The Dow Chemical Company) and TS-1catalyst (10.0518 g, Si/Ti˜30) were added to a 750-mL jacketed glassreactor with a stainless steel cooling coil, thermocouple, mechanicalstirrer, addition funnel, N₂ purge with gas scrubber, and refluxcondenser/cold finger combination. 30 wt %/aq. hydrogen peroxide (60.01g) was charged to the addition funnel, and then added to the reactorslowly after the allyl chloride/catalyst mixture was brought toapproximately 25° C. The mixture was stirred at 600 rpm, and thereaction was brought up to 40° C. by the reaction exotherm andmaintained at approximately 40° C. using the cooling coil.

After 60 minutes, the reactor contents were drained equally into two 250mL centrifuge tubes, and then centrifuged at 3000 rpm and 0° C. for 30minutes. The liquid was decanted from the catalyst into a separatoryfunnel, where the organic and aqueous phases were collected separately.Both phases were analyzed by GC; and the amount of peroxide remainingwas determined by titration with sodium thiosulfate. The results ofComparative Example B are reported in Table I.

TABLE I Reaction TS-1 H₂O₂ Allyl MeOH T Time H₂O₂ CMP/epi MCH/epiEXAMPLE (wt %) (wt %) (wt %) (wt %) (° C.) (minutes) Yield Selectivity(wt/wt) (wt/wt) Example 1 1.5% 5.7% 80.7% 0% - p.t 25 300 89.2% 89.8%0.004 0.011 Comp. Ex. A 1.7% 6.3% 28.5% 49.9% 40 75 92.1% 97.8% 0.0200.004 Example 2 2.1% 3.8% 85.1% 0% - p.t 40 60 84.2% 84.8% 0.006 0.025Comp. Ex. B. 2.1% 3.8% 85.1%  0.0% 40 60 76.3% 80.7% 0.000 0.071Footnotes for Table I: “Yield” = (amount of epi produced)/(maximumamount of epi at full H₂O₂ conversion); “0% - p.t.” = catalyst waspretreated with methanol in accordance with the invention and no furthermethanol was added; “CMP” = 1-chloro-3-methoxy-2-propanol; “MCH” =1-chloro-2,3-propanediol (monochlorohydrin); and “epi” =epichlorohydrin.

The present invention is advantaged over prior art such as thoseconditions used in Comparative Example A because the epichlorohydrinyield is preserved, while the losses of epichlorohydrin to byproducts isreduced. The present invention is further advantaged because it does notrequire the use of amounts of methanol of 50 wt % or more, whichfacilitates separation and isolation of the desired epichlorohydrinproduct.

The present invention is advantaged over prior art such as thoseconditions used in Comparative Example B and Chinese Patent ApplicationNo. CN 200710039080.1 because the present invention provides an increasein epichlorohydrin yield by almost 10%, while the epichlorohydrin lossesto byproducts are reduced by over 50%.

While the present disclosure includes a limited number of embodiments,the scope of the present invention should be limited only by theattached claims and not by the embodiments herein as other embodimentsare possible to those skilled in the art having benefit of thisdisclosure.

1. A multiple liquid phase composition, useful for preparing an oxiraneproduct, comprising a reaction mixture of: (a) at least one olefin;wherein the olefin is selected from one of (i) an aliphatic olefin orsubstituted aliphatic olefin, with the proviso that the aliphatic olefinis not propylene, (ii) a cycloaliphatic olefin, (iii) an aromaticolefin, (iv) a cycloaromatic olefin, and (v) mixtures thereof; (b) atleast one peroxide compound; and (c) a titanium silicalite catalyst withMFI structure (TS-1 catalyst) pretreated with methanol at a mole ratioof methanol to TS-1 catalyst from 0.1:1 methanol:TS-1 catalyst to 100:1methanol:TS-1 catalyst at a temperature of from about −20° C. to about60° C. for about 1 minute to about 24 hours and air-dried such that atleast a portion of the methanol is chemically bound to the activatedcatalyst and a portion of the methanol is not chemically bound to theactivated catalyst; and wherein the fraction of titanium that ischemically bonded with methanol in the activated catalyst comprises from50% to 200% as determined by IR spectroscopy at a frequency of 950-970cm⁻¹.
 2. The composition of claim 1, wherein the at least one olefincomprises allyl chloride; and the at least one oxirane product comprisesepichlorohydrin.
 3. The composition of claim 1, wherein the at least oneperoxide compound comprises hydrogen peroxide.
 4. The composition ofclaim 1, wherein the titanium silicalite catalyst is in the form of asolid activated catalyst and wherein said catalyst maintains itsreactivity in the epoxidation reaction.